Field of the Invention
The present invention is directed in general to semiconductor devices and methods for manufacturing same. In one aspect, the present invention relates to the fabrication of semiconductor devices or integrated circuits with optical and electrical interconnect circuits and devices.
Description of the Related Art
in information systems, data signal information is communicated between devices and circuits using different types of signal connections. With electrical conductor-based connections, such as conventional wires or through silicon vias (TSVs), there are power and bandwidth constraints imposed by the power requirements, minimum device footprint requirements, and physical limitations of such conductor-based connections. For example, stacked die modules have been proposed to provide high density information systems, but the power consumption and associated heat dissipation requirements for communicating data signals between stacked die modules using conductor-based connections can limit the achievable density. In addition, the bandwidth of such stacked die modules is limited by the number and inductance of TSVs and other conductor-based connections for such die stacks. To overcome such limitations, optical interconnect and communication systems have been developed as a way of communicating at higher bandwidths with reduced power. With such optical systems, a monochromatic, directional, and coherent laser light beam is modulated to encode information for transfer to other devices or circuits of the system, typically by transferring modulated light signals along an optical fiber or waveguide path. However, there are a number of challenges with using optical waveguides to replace electrical interconnects for transferring information between different integrated circuit (IC) chips in a system in terms of cost, complexity, and control requirements. These challenges arise from the tight alignment tolerances required to meet information transmission requirements and other use factors that can disrupt alignment during device operation. Attempts have been made to overcome or reduce the challenges of using optical interconnects by using massive parallel interconnect systems which have separate electrical and optical interconnects to transfer electrical and optical information to or from an integrated circuit (IC) chip or system. Unfortunately, such massive parallel interconnect systems can require a large amount of die area and power, and as a result, the existing solutions for providing speed interconnects between multiple semiconductor die without increasing power requirements or die size is extremely difficult at a practical level.
It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the drawings have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements for purposes of promoting and improving clarity and understanding. Further, where considered appropriate, reference numerals have been repeated among the drawings to represent corresponding or analogous elements.